Periodic Classi...

What type of oxide would Eka-aluminium form?

The element with the atomic number $$9$$ resembles with the element having the atomic number:

The element in between lithium and potassium according to Dobereiner's classification is:

Newlands assumed that only ______________ elements existed in nature.

State true or false.
1. Position of isotopes was clearly defined in Mendeleev's periodic table.
2. Position of lanthanides and actinides was clearly defined in Mendeleev's periodic table.

After the classification of elements study of elements become____________.

Which of the following elements has the maximum number of outermost electrons?

Which of the following is a defect in the Mendleev's periodic table?

In the periodic table, the elements having greater non-metallic character are placed at which corner of the periodic table?

What is the valency of potassium with atomic number $$19$$?